"I wouldn't tolerate my own children behaving this way towards women and I cannot and will not condone my own candidates dealing with women in this fashion either," Senator Hanson said in announcing she'd accepted his resignation.

"Then they may have to either put in more renewable technology, or find a better way to measure their carbon pollution, or change production process — there is a cost to that," Mr Shorten said during a commercial radio interview.

"Now, I can't tell you what that cost will be because the company's going to try to do it in the least-cost way."

There was, however, a billion-dollar price tag the Opposition leader was willing to talk about.

He used a trip to a school in the marginal Perth electorate of Swan to announce Labor would help schools to install solar panels.